Variable speed fluid drive transmission



Aug. 15, 1944. J. s. BYRNE VARIABLE SPEED FLUID DRIVE TRANSMISSION File d Sept. 8, 1941 '7 Sheets-Sheet 1 INVENTOR. H JOHN S. BYENE A T'TORNEK 4- J. 5. BYRNE 2,355,780

I VARIABLE SPEED FLUID DRIVE TRANSMISSION J HN BYE/v 5 Aug. 15, 1944. J. 5. BYRNE VARIABLE SPEED FLUID DRIVE TRANSMISSION Filed Sept. 8, 194]. 7 Sheets-Sheet 4 INVENTOR. JoH/v 5'. BYE/V5 Aug. 15, 1944. J. 5. BYRNE 2,355,780

VARIABLE SPEED FLUID DRIVE TRANSMISSION Filed Sept. -a, 1941 7 Sheets-sheaf. 6

v I INVEAI'TOR. E JOHN S. .BYENE a. XM'.

NTTOENEK Aug. 15, 1944; J. 5, gm 2,355,780

VARIABLE SPEED FLUID DRIVE TRANSMISSION I m- INVENTOR.

.F'Jfizlfil JOHN S. BYRNE BY A TTORNE'Y,

Patented Aug. 15,1944

VARIABLE SPEED FLUID DRIVE TRANSMISSION John S. Byrne, Oakland, Calif.

Application September 8, 1941, Serial No. 409,965

(Cl. Gil-53) Claims.

My invention relates to variable speed transmissions, ahd particularly to a fluid transmission arranged to operate through a continuously variable series of ratios between the speeds of the driving and driven shafts.

Methods of transmitting an even flow of power from a prime mover to a load through a considerable range of speeds have been given a great deal of attention. A number of arrangements have been developed using a fluid medium, in which a stress may be set up by direct means, such as a reciprocating pump piston, or to which a high momentum may be imparted, as in centrifugal pumps, and the output controlled by varying the piston stroke or area, the ratio of effective areas between driving and driven impeller blades, the size of an orifice between power input and power output chambers, or equivalent means.

All such methods have, certain drawbacks, an example of which is the leakage past adjacent impellers, or the mechanical complications and losses attendant on reciprocating-pump action.

In the present invention, the fluid medium is circulated from the driving chamber to a driven chamber and back, the entire operation taking place in a sealed housing to prevent leakage. The driving force is applied to the fluid through rockable rotary impeller blades, and a similar set of blades, in turn driven by the fluid, transmitsthe power to the load. A continuous variation in the speed and torque ratios is obtained jects are exemplary only of the purposes of my invention, and that the structural embodiments shown may be modified as required to adapt it to such other uses as may be deemed advisable. In the drawings: Fig. 1 is a perspective view of the assembled device.

by inversely changing the relative areas effective in the driving and driven impellers.

The objects of my invention are: The provision of an efllcient means of varying, through an infinite number of steps, the speed ratio between a driving and a driven member;

To provide a positive action transmission of fluid type;

To eliminate slippage in a fluid transmission; To provide areadily reversible fluid transmission; To permit infinite variations in torque delivered to a'load; and v To deliver very high starting torques to a load and progressively change to the lower torques required to maintain operation at running speed, without perceptible steps in the changing or the torque and speed ratio's.

These and other objects will beapparent to those skilled in the art from the following description of a preferred embodiment of my .invention. It is to be understood that these ob- Fig. 2 is a sectional side view of my transmission,.set to operate at a 1:1 speed ratio.

Fig. 3 is a view similar to that of Fig. 2 but showing the device set to operate at a speed ratio of substantially 8: 1.

Fig. 4 is a sectional view, taken along line IV-IV of Fig. 3, showing the cam plate and track controlling the impeller blade positions.

Fig. 5 is a transverse section, showing the impeller blade mounting bores androds, taken on line V-V of Fig. 3.

Fig. 6 is a transverse section, taken on line VI-VI of Fig. 3;

Fig. '7 is a perspective detail of one of the impeller blades.

Fig. 8 is a transverse section, taken along line VIIIV1'1I of Fig. 2, showing the working chamber, driving impeller blades, and ratio-changing mechanism.

Fig. 9' is a transverse sectional view, taken along line IX-IX of Fig. 2, showing the arrangement of the driven end'elements.

Fig. 10 is a perspective, broken-away view of the driving member.

Fig. 11 is a horizontal section through the housing, taken in the plane or the drive shaft axis, the other elements being omitted for clarity.

Fig. 12 is a side view of the speed ratio changing elements and housing, illustrated in section, with other parts removed for ease of understanding.

Fig. 13 is a schematic transverse sectional view of an alternative embodiment of my invention, arranged to permit reversal and set for rotation of both shafts in the same direction,

Fig. 15 is a sectional view or the reversing mechanism, taken in the same plane as Fig; 14 but set for rotation of the driving and driven shafts in the same direction.

Fig. 16 is a. top schematic view of the reversins %eclia5nism inposition corresponding to that of Returning now to Fig. l, the transmission, generally denominated I, is interposed between the driving shaft 2 and the driven shaft 4. The driving shaft '2 is attached to any conventional prime mover (not illustrated) and the driven shaft is connected to'a load, also omitted from the figures.

The driven shaft 4 has been illustrated as being of a diametersubstantially exceeding that of the driving shaft 2, since it is contemplated that the usual mode o'f 'operation will be that of reducing the speed and increasing the torque in the driven shaft. Obviously, these relations may be varied in accordance with the needs of the particular service for which the transmission is designed.

A cylindrical driving member 5 is'secured to or formed integrally with the driving shaft 2, and'rotates within a cylindrical driving end bore 6 formed in the driving end housing I of transmission I. The outer end of chamber 6 is closed by a driving end plate 9 incorporating a packing gland Ill, of conventional design suitable to restrain high pressure, secured to the housing I by usual means, such as bolts, omitted from the drawings as an aid to clarity.

At the opposite or driven end ll of housing I is formed a cylindrical driven end bore l2, closed terminally about driven shaft 4 by a driven end plate I4 having a pressure-sealing packing gland l5 similar to gland I formed integrally therewith. Within the driven end bore I2 is rotatably mounted a driven member I1, with which is formed integrally a driven shaft 4. Oil reservoirs l3 and I8 are mounted along the sides of the device and feed thereinto, as will be set out hereafter.

Apart from dimensional differences in the driven and driving shafts 2 and 4 and between the sealing glands l0 and I disposed therearound, both ends of the device are symmetrical,

as so far described.

Driving member 5 has formed therein three evenly spaced cylindrical bores I9, 20 and 2i, in which are seated driving impellers 22, 24 and 25, respectively. Driven member I! has corresponding bores 26, 21 and 29 in which ar disposed driven impellers 30, 3| and 32, respectively. Since the driving impellers are identical, only one will be described in detail together with its accompanying mounting in the driving member 5. Impeller 22 comprises a cylindrical body portion 34 fitting snugly within bore 1 9 and a blade portion 35 formed by cutting away the body portion on one side at 36, so that it can extend into a compression chamber, described hereafter, of lesser diameter than bore l9.

Driving member 5 and the driven member I1 are partially enclosed, on their adjacent sides by a reduced diameter central portion 31 of the housing which extends between the driving end housing 1 and the driven end housing portion I l. Inner end walls 40 and 4| join central housing portion 31 to the housing portions 1 and II, respective y, and act to prevent axial movement of the driving and driven members 5 and I1.

Within the central housing portion 31 the sur-, face is not a cylinder but a compound of two coaxial cylindrical sectors of different radii. The upper portion 42 has a smaller radius than does the lower surface 44, and the two surfaces are connected at the sides by portions 45 of changing curvature, aifording a smooth transition therevpartially for the remainder thereof.

tion of the circumference of each bore being' cut away by the reduction in diameter of th member 5. The inner ends of bores I9, 20 and 2| are closed transversely by a cylindrical inner driving end plate 41 secured to reduced diameter portion 46 by conventional means, such as bolts 49.

The impeller 22 is thus housed within a congruently. curved supporting chamber 56, surrounding it completely for a portion of its length and The impeller is freely slidable axially of this supporting surface and along a square shaft 56 passing centrally through the impeller and journaled in the end plates 53 and 41. The cutaway surface 36 of the impeller is made with the same radius of curvature as the upper surface 42 of the central chamber 48 so that the impeller may slidably engage therewith during any part of its traversal axially along square shaft 50 between the terminal limits defined by the end plates 53 and 41.

It will be noted by reference to Fig. 8 that when the impeller 22 is at top dead center the surface 36 (Fig. 7) is in contact with small diameter impeller and the housing. Thus a stress may be set up in the fluid medium by rocking the impeller blade 22 and continuing rotation of the driving member 5. The mechanism for producing the proper angle of rocking of the impeller is illustrated in Fig. 4 and in dotted lines in Fig. 8.

The square shaft 50, on which the impeller blade is mounted, extends through a suitable journal 54 in outer end 53 of driving member 5.

" A cam lever 55 is fixed thereto and is movabl between. Into th chamber 48 thus formed exwithin an arcuate recess '56 cut into the outer side of driving member outer end 53. Cam roller 51 is rotatably mounted on cam lever 55 and projects axially from member 5 into engagement with a cam track 59 cut into driving end plate 9.

Track 59 is shaped to cause lever 55 to hold the cut-away impeller surface 36 congruently with the upper chamber surface 42 as it moves through the upper part of its rotational arc, and to turn the impeller gradually as it travels past the variable radius portion 45. so that when it reaches the lower curved chamber surface 44, the portion of greatest radius of curvature, the leading edge 5! will engage therewith to form a closure or partition, shutting off the chamber space 52.

Further rotation of'the driving shaft 2 will then.

chamber 52 through return passage 62. The shape of the passages 60 and 62 between the chambers 52 and 6|, respectively, is shown to best advantage in Figs. 11 and 12, in which the impellers have been removed for clarity.

- andspeed,'aswill of each passage is ,iormed reduced diameter member i with the collar ll.

' omitted iromall the figures drivingdmpeliers 22, u and 2s central bores lland l1.' v 1 endbore l2 areseen, definedterminallyattheir inner endwalls ll and ll. Between the chamber llandthechamber resp nding reduced diameter driven member portion 14, respectively, extend when the device is completely assembled, the collar ll is shown. This collar ll provides the adjustment of torque be seen hereaiter.

Passages ll and l! are rectangular slots iormed longitudinally through the side walls oi the central portion 31 oi the housing and closed on the outside by side cover plates ll and II attached to the housing by bolts II. The inner boundary by the outside oi collar ll. Oil ieed pipes ll and ll irom II and II communicate with passages ll and ll through plates and II, respectively, to main,-

tain the supply of oil. As oil is withdrawn ircm reservoirs l3 and I8, air is drawn therein through snifter valves 6.8, shown in Fig. 8, and provides a cushioning eiiect during operation.

The driving impeller shafts ll and the inner end plate 41 in which they are iournaled extend into the collar ll at the driving end,

reservoirs while from i ll, into which the reduced diameter driving member portion ll and the corv nected by housing the driven end, the reduced diameter driven end member ll extends thereinto.- The driven end 14 is identical with the corresponding driving end member ll except that it is oi somewhat greater length, when the driven end torque is to be equal to or greater than the driving end torque, as shown. iii a speed increase is desired, the driven end member would be'made shorter than the drivingend member. The impeller bores in member II are terminated centrally by a cylindrical inner driven end plate ll secured thereto by suitable means, as bolts ll, and having therein journals I'l ior the inner end of square shaits ll. The inner end plates l1 and]! are separated by a short distance, so that there may be nointerierence by either with the rotation oi the other.

About the square-shaits ll and ll and based against the end walls of the driving and driven "members 5 and I! are disposed compressedsprings ll. These springs tend to force the impeller blades ter oi the housing and into contact terminally Thus at all times both driving anddriven impeller blades extend into chamber ll as iar as permitted by collar ll, which thereby divides the chamber ll into the chamber is and the chamber ii. The collar ll is traversible axially oi chamber ll by means oi a rack ll formed along the bottom external crank II. Traversing collar axially oi chamber ll exposes an' inversely varying area oi the driving and contact with the fluid medium.

. In order to permit this axial traversal oi the impellerblades, I have provided communicating central bores ll and 01 in driving member'l and drivenmember i1. Bore ll opensbehlndthe into impeller passages ll. Bore bores ll, ll and Ii through l'l opens behind driven impellers ll, ll and ll passages to. when driven impeller blades to which has been 1 ior the sake oi clarity.

.en end,'less friction. Ii as in Fig. 2 so that within collar ll, respectively. Driving bore space Ill and driven borespaee IllIare directly conpassages 2H grooved terminally at Ill to permit iunctioning when the impellers are at the inner limits of their traverse. This system oi passages allows shifting the impellers axially without any hydraulic binding.

The work done at thedriven shait 4 will be less iriction, as that transmitted to Operatin as the device does in a closed chamber, the product 0! the turning moment and the impeller area at the driving end will equal the corresp nding product at the drivthe collar ll is positioned equal impeller areas are .ex- II and ll, the torque and Ii collar ll is moved to the position oi Figs. 3 and 12,, the ratio of exareas and hence oi torque will be roughly 1:8 between the driving and driven ends. That is, driven shaft 4 will revolve once ior every eight revolutions of driving shait' 2,.but will exert eight times as much torque, or turning moment. The smaller the driving end impeller blade area is exposed, the'greater in chambers speed ratio will be 1:1.

j end.

along the shaitsll toward the cenoi the structure oi rigs.

thereoi and meshing with a pinion l2 driven through a shait ll by an vides ior iormation oi l0 traversed.

The same sort oi the driven end to control the angular position oi the impeller blades as is used at the driving end. Arcuate recesses ll receive cam arms ll fixed on square shaits ll, and cam rollers ll, pivotally mounted on arms ll, project into a cam track It cut into end plate ll. The transmission as thus iar described allows an operator to vary the speed and torque delivered to a load over'wide limits, with rotation in a fixed direction, turning opp tely to the drivins shait.

In-Plgs. 18-18, I have illustrated a modification 1-12, which will permit reversing the direction oi rotation oi the driven shait at will. An expanded housing ill procylindrical valve-chambers Ill and ill along each side thereoi parallel to the axis oi the drive shaits 2 and 4' in a substantion to that occupied by the passages ll and I! in the showing oi Figs. 11 and 12 and space ior suitable valve passages described hereaiter. Cylindrical valves Ill and m are slidabiy disposed in these chambers and are traversed axially thereoi in unison by valve rods Ill and Ill extending out oi housing ill through suitable sealed glands ill and Ill and fixed to a transverse sages III-and Ill are iormed in'communlcation with the opposite ends oi the valve chambers Ill and ill, respectively, to permit tree traversal oi. the valves llland ill in a bath oi oil or other Each oi the cylindrical valves ill and Ill comprises an'elcnsate solid body. I II, in which is iormed along chamberl It and a short chambor lll, separated by awall ill. chamber ill A correspondthe reduction oi speed and cam arrangement is used at the driven shait always valve control bar ill. Pasis elongated axially of the valve and is ope through lateral port I 20 when in reversed position, as shown in Figs. 15 and16, and into, both chambers 52 and GI when in normal position, as shown in Fig. 14. Chainber' H8 in valve I04 also has a downwardly opening port I2l communicating in reversing position with a lower reversing passage I22. Chamber H of valve I has an upwardly opening port I24 communicating in reversing position with an upper reversing passage I25.

In the normal position of the valves, ports I 2| and I24 are out of registry with upper and lower reversing passages I22 and I25 as shown in Fig. 14. The lateral ports I20, being open to both chambers 52 and BI, permit normal flow of oil through valve chambers H6 and around body partitions I28 which otherwise block communication therebetween. This mode of operation is identical with that of the prior embodiment.

In the reversing position of the valves, as shown in Figs. 13, and 16, the fluid under pressure from the driving chamber 52 is delivered into the short chamber III of valve I05 through a lateral valve port I2I, as shown in Fig. 16, and passes downwardly through a port I29 as indicated by the arrow I29 from chamber Iil into the lower reversing passage I22. Lower reversing passage I22 guides the fluid downwardly, across beneath the working chambers and upwardly at the opposite end of the housing where it enters valve chamber IIB of valve I04 through the downwardly opening port I2I as indicated by the arrow I2I', and emerges through the laterally opening port I into the chamber 6|. After performing its work, it leaves chamber 6| through the lateral port I20 of valve I05, emerges upwardly through port I24 as indicated by arrow I24 into upper reversing passage I25, is carried thereby diagonally above the working chambers,

, down through upwardly opening port I 30 into short chamber III of valve I04, and is returned from the short valve chamber through a lateral port I3I, as shown in Fig. 16, into the chamber 52 for a repetition of the cycle.

The reversing mechanism as described is substantial, simple in operation, and has no complicated parts to give trouble, and no special means are necessary to seal the valve elements.

In summary, my invention meets the need for a transmission affording a continuously variable ratio of torques. Any ratio desired may be utilized by a simple lever control. Few working parts are required, and it is not necessary to have extremely close tolerances. Lubrication is simplified, sinceall parts operate'in a bath of oil continuously. A modified embodiment is shown foruse when it is desired to reverse the direction of rotation.

I claim: g

1. A fluid transmission, comprising a housing, an eccentric bore formed in said housing. a collar congruent with and axially slidable within said eccentric bore, passages formed in said housing forming a loop through said bore around said collar, impeller-supporting members rotatably disposed within said housing, reduced diameter impeller-supporting member portions extending axially toward the center of said housing, a bore formed axially in said collar and arranged to receive rotatably therein said reduced diameter impeller-supporting member portion, impeller blades rockablymounted in said impeller-supporting members, cam tracks formed at each end of said housing, a cam arm fixed into the chamber 0|,

to each of said blades and arranged to engage one of said cam tracks to rock said blade into sealing contact with said eccentric bore, said blades terminally engaging said collar, resilient means for urging said :blades axially against said collar, and means for traversing said collar axially of said housing.

2. A fluid transmission, comprising a housing, an eccentric bore formed in said housing, a collar congruent with and axially slidable within said eccentric bore, passages formed in said housing forming a closed loopthrough said bore around said collar, impeller-supporting members rotatably disposed within said housing, reduced diameter impeller-supporting member portions extending axially toward the center of said housing, a bore formed axially in said collar and arranged to receive rotatably therein said reduced diameter impeller-supporting member portion, impeller blades rocka-bly mounted in said impeller-supporting members, cam tracks formed at each end'of said housing, a cam arm fixed to each of said blades and arranged to engage one of said cam tracks to rock said blade into sealing contact with said eccentric bore, said blades terminally engaging said collar, resilient means for urging said :blades axially against said collar, a rack formed axially of said collar, a pinion disposed in said housing engaging said rack, external means. for rotating said pinion, and means for permitting shifting of fluid from end to end of said housing between said impeller mounting members independently of flow through said closed loop.

3. In a variable ratio transmission, the combination of a housing, a drive shaft and a driven shaft journaled in said housing at opposite ends thereof, an impeller mounting member fixed to said drive shaft, an impeller mounting member fixed to said driven shaft, a reduced diameter portion extending axially from each or said impeller mounting members toward the center of said housing, an eccentric chamber formed centrally of said housing, a similarly eccentric col-- lar arranged to fit slidably therein and bored to receive said reduced diameter portions movably therewithin and defining two portions of said chamber, bores formed in said driving and driven impeller mounting members, square shafts mounted coaxially in said bores, blades disposed rockably in said bores and slidably mounted on said square shat means for urging said blades parallel to the axis and toward the center of said housing, a cam track formed in each endof said housing, a cam arm fixed to each of said square shafts and engaging said track to maintain a sliding seal between said blades and said eccentric chamber, passages formed axially-in said driving and driven impeller mounting member: communicating between the outer ends of said bores, passages formed in said housing for communication between the inner ends of said bores,

axially from each of said impeller mounting portion extending members toward the center of said housing, an eccentric chamber formed centrally of said housing, a similarly eccentric collar arranged to fit slidably therein and bored to receive said reduced diameter portions movably therewithin and defining two portions of said chamber, bores formed in said driving and driven impeller mounting members, square shafts mounted coaxially 'in said bores, blades disposed rockably in said bores and slidably mounted on said square shafts, means for urging said blades parallel to the axis and toward the center of said housing, a cam track formed in each end of said housing, a cam arm fixed to each of said square shafts and engaging said track to maintain a sliding seal between said blades and said eccentrlc chamber, passages formed axially in said communicating between the outer ends of said bores, pressure medium passages connecting the said portions of said chamber, and valves dis- ,an impeller mounting shaft joumaled in said housing at opposite ends thereof, an impeller mounting member fixed to said drive shaft rotatably within said housing,

member fixed to said driven shaft rotatably within the opposite end of said housing, a reduced diameter portion extending axially from each of said impeller mounting members toward the center of said housing,

an eccentric chamiber formed centrally of said housingfa similarly eccentric collar arranged to fit slidably therein and bored to receive said reduced diameter and defining two portions of said chamber, bores formed in said driving and driven impeller mounting members, square shafts mounted coaxially in said bores, blades disposed rockably in driving and driven impeller mounting members said bores and slidably mounted on said square shafts, means for urging said blades parallel to the axis and toward the center of said housing, a cam track formed in-each end of said housing, a cam arm fixed to each of said square shafts and engaging said track to maintain a sliding seal between said blades and said eccentric chamber, and means for selectively controlling the path of fluid to said portions of said chamber.

. JOHN S. BYRNE.

portions movably therewith-in 

